the gap between revenues and expenditures for a government (over a given period of time); often referred to as an internal deficit or public deficit.
The public deficit accumulates over each time period (usually a year) into what is known as the public debt.

According to Keynesian and Neo-Keynesian economic theory, fiscal deficits are usually the most effective tool for stimulating economic activity; the actual choice of how the money is spent is less important.

In the USA, most states are not allowed to run fiscal deficits. In other federal republics, such as India and Argentina, they are allowed and frequently account for much of those countries' internal deficits.